Scaphidium grandior, Löbl, 2025

Löbl, Ivan, 2025, On the identity of Scaphidium grande, with resurrection of S. inimpressum and S. melanopus and description of two new species (Coleoptera: Staphylinidae: Scaphidiinae), Acta Entomologica Musei Nationalis Pragae 65 (1), pp. 15-20 : 19-20

Scaphidium grandior sp. nov.

( Figs 5 , 10 )

Type material. HOLOTYPE: J, labelled: ʻTHAILAND, 1000-1600m Chiang Mai, 26.iv.-9.v.1996, 18°49’N 98°54’E, Doi Pui mt. lgt.S. Becvarʼ ( NMPC) . PARATYPES: same data as holotype, 1J 3♀♀ ( NMPC, MHNG).

Description. Body length 5.35–6.05 mm, width 3.75–4.30 mm. Body black, with brown or reddish abdominal apex. Antennae with antennomeres I to VI dark brown, apices of antennomeres II to VI lighter, antennomeres VII to XI black. Femora black, meso- and metafemora with reddish fascia. Tibiae black. Tarsi brown or rufous. Frons flat, at narrowest point 0.34–0.36 mm wide, entirely punctate, or impunctate on narrow area in level with posterior eye margins; punctation not confluent and not elongate. Eyes large, eye width in dorsal view about 1.7 to 2.2 times as large as narrowest point of frons. Vertex distinctly punctate, with strigulate microsculpture. Punctation on clypeus finer and sparser that that on anterior part of frons. Pronotum raising above elytra, with lateral contours weakly sinuate, anterior margin straight in dorsal view, anterior margin stria with uninterrupted punctures row; antebasal puncture row impressed; disc densely punctate, punctures round, smaller than puncture intervals, area between antebasal puncture row and basal margin impunctate. Elytron with humeral hump hardly developed, disc in middle weakly convex, moderately inflexed and slightly impressed apicad; punctation on most of disc fine and sparse, finer and sparser than pronotal punctation, becoming coarse and dense near apex, on apical seventh nearly as pronotal punctation; disc with one to three inconspicuous rows of slightly larger punctures; basal stria gradually impressed laterad, with coarse punctures about as large as punctures in pronotal antebasal row; sutural stria rather coarsely punctate, adsutural area entirely raised and roof-like. Prosternum lacking microsculpture, anterior prosternal margin with coarse, almost confluent, not elongate punctures, anterolateral margins with a few impressions. Hypomeron smooth. Mesanepisternum and lateral parts of metaventrite extremely finely and very sparsely punctate, lacking microsculpture. Mesanepisternum with anterior bead widening laterad, delimited by stria not reaching posterior margin. Metaventrite impressed on apicomedian area. Ventrites with densely reticulate microsculpture. Ventrite I distinctly punctate on basomedian area and with a few distinct punctures scattered on lateral areas. Ventrites II to IV with elongate basal striae evanescent on median areas, each with four macrosetae, very finely and sparsely punctate.

Male. Profemur with ventral side flattened, bearing two rows of tubercles. Protibia much shorter than mesotibia and shorter than profemur, weekly arcuate in lateral view, throughout evenly thick, bearing rows of tubercles at inner side, angulate near apex. Metaventral setal patch covering nearly entire mesal area of metaventrite, setae light brown, recumbent, moderately long. Aedeagus ( Figs 5 , 10 ) 2.08–2.14 mm long.

Differential diagnosis. This new species is similar to S. grande . It may be distinguished by its smaller body size, finer elytral punctation, and the anterior bead of the mesanepiternum widening laterad, in addition to the distinctive aedeagal characters. The comparatively narrow body resembles that of S. longum Tang & Li, 2010 , while the male protibiae of S. grandior sp. nov. are significantly shorter than those in the latter species. The structures of the internal sac of S. grandior sp. nov., with acute basolateral angles of the trapezoid sclerite in combination with a single saucer-shaped subbasal sclerite and incurved basolateral stripes, are unique.

Etymology. The species epithet grandior is the comparative degree of the Latin adjective grandis, which means great, grown up or powerful.

Distribution. So far known only from northwestern Thailand.

Figures

Figs 1–5. Aedeagi in Scaphidium grande group. 1 – S. grande Gestro, 1879 (Rumah Tuan Village, Sarawak); 2 – S. inimpressum Pic, 1920 (Defulan Trail, Taiwan); 3 – S. melanopus Achard, 1924 (lectotype); 4 – S. metafasciatum sp. nov. (holotype); 5 – S. grandior sp. nov. (holotype). Scale = 0.5 mm.

Figs 6–11. Internal sac of median lobe in Scaphidium grande group. 6 – S. grande Gestro, 1879 (Rumah Tuan Village, Sarawak); 7 – S. inimpressum Pic, 1920 (Defulan Trail, Taiwan); 8 – S. melanopus Achard, 1924 (lectotype); 9 – S. metafasciatum sp. nov. (holotype); 10 – S. grandior sp. nov. (holotype); 11 – Scaphidium sp. (Huisun, Taiwan).